Managing and controlling power consumption is a key task for low power applications relying on a limited power supply, such as battery powered applications. Communication systems using battery powered equipment may switch the equipment from an active or ON mode to a standby or OFF mode with reduced functionality and reduced power consumption. For example, receivers in low power applications such as radio receivers used in e.g. mobile phones or automotive applications, such as passive entry systems or tire pressure monitoring systems, are often automatically switched to a standby mode with reduced power consumption, since data are not received as a continuous signal stream but occasionally in bursts between idle periods. In order to switch the receiver device back to active mode, where complete receiver functionality is available, a wake-up procedure is performed. A receiver cyclically changes between OFF mode and ON mode. FIG. 1 shows a schematic diagram of a first example 10 of a power consumption P over time t of a receiver switching between ON phases 12, 14 and OFF phases 16, 18, 20. When switching to ON mode, the receiver checks, if a signal is being received and a wake-up must be performed.
Moreover, FIG. 2 shows a schematic diagram of a second example 22 illustrating that in order to consume as little power as possible, wake-up is often performed as a power up sequence with several steps to detect an incoming signal and activate functions when needed. Checks for detecting a valid incoming signal are performed progressively or successively. With each further step, checks become more and more stringent, which often requires more complex and thus more power consuming analysis functionality, as the probability of receiving a valid incoming signal increases. If a valid signal is received, the step sequence goes up to completion and the received message is sent to a buffer for further processing by a data processing device. In a receiver system, this may, for example, be a microcontroller unit (MCU), a digital signal processor (DSP), a general purpose processor (GPP), a central processing unit (CPU) etc. FIG. 3 shows a schematic diagram of a third example 24 of a power consumption P over time t of a receiver switching between ON phases 12, 14 and OFF phases 16, 18, 20. As illustrated in FIG. 3, power consumption P over time t can be reduced by terminating the power up step sequence after the first detection level 26, 28 and switching back to OFF mode 18, 20, in case no signal is received. However, as illustrated in FIG. 4 showing a schematic diagram of a fourth example 30, in case of interference or other unwanted or invalid signals, the power up sequence may not be terminated immediately but may continue for some additional steps 30, 31 or even all of the steps of the sequence. In contrast to a complete valid wake-up, where all steps of the wake-up sequence are performed and the receiver finally provides fully activated functionality and receives a valid incoming signal, no valid signal is received during a false wake-up. If the false wake-up is detected before completion of the full wake-up procedure, the wake-up may be terminated before completion. These false wake-ups cause power consumption above the actually required minimum, since more sub-modules of the receiver need to be active during a longer time. In case of permanent interference, numerous false wake-ups can lead to a fast discharge of the battery powering the receiver.